NORTHAMPTON – Proponents of saving the dam at Upper Roberts Meadow Reservoir have what appears to be one more chance to make their case Wednesday, following a City Council resolution that essentially says the city is still listening to them.

The council voted 7-0 Thursday to hold a public forum on Oct. 27 so that the public can hear consultants for both the Friends of the Upper Roberts Meadow Reservoir Dam and the Board of Public Works. A representative from the Massachusetts Office of Dam Safety will be there as well.

The state has given Northampton a Nov. 1 deadline for coming up with a schedule for either repairing or breaching the 1883 dam after giving it its highest hazard rating. According to the Office of Dam Safety, as many as 250 homes in Leeds could be endangered should the dam give way and cause the larger dam below it to breach.

The Friends group has disputed that scenario along with the cost estimate for restoring the dam and using it for hydropower. This has resulted in a battle of numbers between the group and the Board of Public Works.

GZA GeoEnvironmental Inc., an engineering firm hired by the city, concluded that it would be cost prohibitive to save the dam for hydropower. Essex Partnership, a company commissioned by the Friends, concluded that the money generated by the sale of hydropower would narrow the gap in cost between taking out the dam and restoring it. Tighe & Bond Inc., a third party hired by the city, found that Essex overestimated the benefits of hydopower. The city has spent $71,450 to date on engineers and consultants regarding the dam debate, according to City Engineer James R. Laurila.

The board has estimated that it would cost $1 million to breach the dam, but said it would consider the alternative if the Friends could come up with the extra $25,000 it would cost to restore it and another $650,000 to maintain the dam over the next 50 years.

The board has already been granted three extensions by the Office of Dam Safety while the debate has played out, but the final Nov. 1 deadline is approaching. The board will take its vote on Oct. 28, the night after the forum. Board chairman Terry C. Culhane said he has heard nothing persuasive from the Friends to date.

“Essex didn’t do an engineering study of the dam,” he said, referring to the Friends’ consultant. “It’s not apples-and-apples.”

Culhane noted that 50 people in Leeds died when a dam in Williamsburg collapsed in 1874 and said the classification for the Upper Roberts Meadow Dam is based on a worst-case scenario.

“I can’t imagine any scenario where there would be a low hazard in Leeds,” he said.

Even if the state were to lower the hazard rating from “high” to “serious,” the city would have to take the same measures, according to Culhane.

Dee Boyle-Clapp, who helped organize the Friends, differs with Culhane, saying the cost of maintaining a restored dam under a lower classification would dramatically decrease the cost. Boyle-Clapp said the group has retained a new consultant who will perform a study on the dam and present those findings at the Oct. 27 forum.

“This is another opportunity for us to inform the public,” she said.

Despite the looming deadline, Boyle-Clapp believes that the City Council can request another extension from the Office of Dam Safety, even though it doesn’t meet for another two weeks.

“One or two councilors can write letters,” she said.

Wednesday’s forum is at 7 p.m. at the John F. Kennedy Middle School. The Board of Public Works meets Thursday at 7 p.m. at 125 Locust St.